FYI - Consumer CF cards are not meant for excessive read/write cycles, which is exactly what a VPU does when it plays an AA prompt, system prompt or appends a logfile.
The 5000 systems use an industrial CF card for this reason; one which is rated at a much higher duty cycle. For example, even though SanDisk calls
this card a model "5000" I'm referring to the Inter-Tel/Mitel 5000.
I like your idea and think your solution will work, just don't know for how long. Don't take this the wrong way, but the Inter-Tel smart guys already crossed this bridge when the 5000 was developed and they decided on industrial CF over consumer CF.